BOSTON (AP)  Prosecutors in Massachusetts have decided not to retry a man who spent 36 years in prison for a murder he says he did not commit.

The Norfolk District Attorney”s Office on Monday dismissed all charges against 66-year-old Frederick Weichel.

Weichel was convicted in the 1980 killing of Robert LaMonica. A judge in April overturned the conviction, saying authorities failed to give the defense a police report suggesting another possible suspect. He was freed on $5,000 bail.

In Monday”s decision, the district attorney”s office said six key witnesses in the original trial have died, and two others have serious health issues. Prosecutors reserved the right to retry Weichel, if new evidence comes to light.